>    The M$IE behaves like this. User submits the form, server processes it
> and sends a redirect to the same URL; user modifies inputs and submits the
> form for the second time. This time IE sends 2 (I said "two"!) POSTs, and
> whaterver server replies (whether it is HTTP 200, or 303, or 404) IE
> complains "DNS Error". Other browsers (I tried Mozilla for Linux and for
> Windows) work fine with the application.

Sorry, I'm going a little off topic with this, but it may be of mild
interest.

I once saw a similar bug that only showed up in IE (Mozilla and Netscape 4.x
didn't exhibit the bug, anyway):

This was an ASP app, and under some conditions, when a user logged in, I'd
write in a javascript alert, which would pop up, and then the page would do
a location.href="...someurl..." to redirect.  The bug was that in IE,
sometimes, the alert would pop up twice before redirecting.  I thought I had
a bug in my logic, or some weird frame interaction, or something.
Eventually, getting really baffled as to the problem, I slapped a packet
logger on the client, and confirmed...  The alert was only coming across the
wire once.  IE just processed it twive for some reason.  I wrote it off as
Somebody-Else's-Problem, and moved on.

Jason Sibre